Sagot :
There could be lots of answers. I'm going with 5 goats and 7 ducks.
x=goats
y=ducks
4x+2y=34
x+y=11
-y -y
x=11-y
4(11-y)+2y=34
44-4y+2y=34
44-2y=34
-44 -44
-2y=10
/2 /2
y=5
x+y=11
x+5=11
-5 -5
x=6
goats=6
ducks=5